#include <stdio.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
int main()
{
    int ret ;
    printf("current : %d.\n", nice(0));

    ret = nice(-10);

    printf("new priority : %d(%s).\n", ret, strerror(errno));

    printf("current : %d.\n", nice(0));

    return 0;
}
